Patients diagnosed with disordered breathing problems, such as sleep disordered breathing, snoring, upper airway flow limitation, hypopnea, apnea, or similar, may rely on a respiratory apparatus, such as a continuous positive airway pressure (CPAP) or a BiLevel positive pressure device, to assist with maintaining an open airway. Other forms of a respiratory apparatus include a ventilator. A ventilator assists a patient to breathe by providing oxygen to the lungs and removing carbon dioxide from the body. A ventilator can be used for a patient that is unable to or has a reduced capacity to, for example due to lung disease, breathe on their own.
A respiratory apparatus may include a flow generator coupled to a patient interface (e.g., mask or cannula, etc.) to generate a supply of positively pressurized gas for supply to the patient's airways at one or more pressures.
A respiratory apparatus may also include one or more sensors, such as a pressure sensor, to monitor characteristics of the breathable gas, such as pressure, to be provided to the patient. Based on the measured characteristics, the apparatus may control adjustments to respiratory parameters such as by changing a treatment pressure above atmospheric pressure to splint open an obstructed or partially obstructed patient airway or a change in a pressure support (PS) to provide ventilation that meets a target volume where pressure support is a difference between an inspiratory pressure and an expiratory pressure. Such adjustments may be made by a controller setting or adjusting the motor speed of the flow generator or the controller setting of an aperture of a relief valve of the system. A false reading by any sensor involved in the control of the breathable gas may yield inaccurate control thereof, which, in turn, may adversely affect patient breathing, comfort or safety.
To ensure accurate performance by a respiratory apparatus, it may be desirable to develop methods for monitoring or detecting the accuracy of sensors, before and/or during use, such as a pressure sensor, or for detecting a fault with such sensors.